Absorbing products are used in various fields of, for example, hygienic materials such as disposal diapers, sanitary napkins, incontinence pads and the like; urine-absorbing materials for pets; materials for city engineering and construction such as a packing material and the like; food freshness preservers such as drip absorbents, heat insulators and the like; agricultural materials such as water-retentive materials for soil and the like.
Especially for hygienic materials and the like, there is a problem that absorbing products which have absorbed a body fluid, in particular, urine, blood, sweat and the like, emit unpleasant odors. It is considered that these odors are putrid smells resulting from decomposition of body fluid components such as urea, proteins and the like with enzymes decomposing the body fluid components which are produced from bacteria ranging through skins and alimentary tracts. For urine, main components of these unpleasant odors are thought to be nitrogen-containing compounds such as ammonia, trimethylamine; sulfides such as hydrogen sulfide; methanethiols; aldehydes and the like.
In order to suppress emission of such unpleasant odors, absorbing materials containing odor adsorbents such as an active carbon, zeolite and the like (See, for example, JP-A 2001-37805 and JP-A 1999-512946), a water-absorbing material containing a water-absorbing resin and a germicide such as a quaternary ammonium salt which kills the above bacteria to prevent putrid smells from gradually increasing (See, for example, JP-A 2000-79159) are proposed. However, the absorbing materials containing odor adsorbents such as an active carbon, zeolite and the like are not effective against putrid smells which increase due to gradual decomposition of body fluid components. Furthermore, the water-absorbing material containing a water-absorbing resin and a germicide such as a quaternary ammonium salt is undesirable in terms of safety because it is possible that the germicide causes inflammation when it contacts with skins or mucous membranes.
Therefore, a compound containing a water-absorbing resin and an antibacterial agent having an inorganic compound incorporating an antibacterial metal such as silver, copper, zinc and the like is proposed (See, JP-A 2001-505237).
Antibacterial agents having an inorganic compound incorporating an antibacterial metal may be generally classified into two groups according to their expression manner of antibacterial properties based on a kind of an inorganic compound as a matrix; an eluting-type antibacterial agent which sustained-releases an antibacterial metal, and a non-eluting-type antibacterial agent which does not sustained-release an antibacterial metal. The eluting-type antibacterial agent expresses its antibacterial property by inhibiting enzymatic activities of microorganisms with eluted antibacterial metals. However, in this type of antibacterial agent, when an organic material exists in a system, the organic material forms salts with the sustained-released antibacterial metal to greatly reduce the antibacterial property. Therefore, in applications for absorbing a body fluid, for example, disposal diapers, sanitary napkins and the like, the eluting-type antibacterial agent has a disadvantage that its efficiency is reduced.